1. Technical Field
This application relates to wireless communication techniques in general, and to an apparatus and method of controlling unsolicited traffic destined to a wireless communication device in particular.
2. Related Art
Some wireless communication devices are known to receive unsolicited traffic. For example, a Code Division Multiple Access (CDMA) 2000 wireless communication device operating in simple Internet Protocol (IP) configuration can receive unsolicited IP packets. Although other non-wireless devices are known to receive unsolicited traffic, techniques traditionally used with non-wireless devices may be inappropriate as there is a significant waste of resources, both in the wireless network, as well as in a wireless communication device, whenever unsolicited traffic gets sent over the air interfaces.
One technique that is known, which partly addresses this problem, involves using a private addressing scheme. However, even if a private addressing scheme is used, this technique may not prevent unsolicited traffic initiated from within the private address space from reaching the wireless communication device. Furthermore, this technique may be unacceptable if a public address is desired, as is the case for example with certain CDMA2000 wireless carriers. Another technique that is known, which partly addresses this problem, involves using a firewall within the wireless communication network. However, firewall rules may have to be manually configured, and may be ineffective if the rules depend on the wireless communication devices addresses, which may be subject to change due to mobility. For example, in the case of CDMA2000, IP address can be dynamically assigned and reused, which may render the firewall rules ineffective for the wireless communication device.
Generally speaking there are three categories of unsolicited traffic which require screening: (a) Stale Session Unsolicited Traffic—When a mobile device stops using an IP address A without first terminating communications previously established to other servers, packets may continue to be sent to the same IP address A. Examples are Virtual Private Network (VPN) packets, Peer-to-Peer (P2P) file sharing, spy ware and many more. Such packets often are sent continuously to the device. Unsolicited traffic can arrive via a stale IP session when a second mobile device acquires IP address A, and starts receiving packets from stale IP session(s), the unsolicited traffic originally intended to reach the first mobile device; and (b) Inter-subscriber Intra-subnet Unsolicited Packets—Subnet constrained broadcasts or serial unicast from one mobile to another are effectively unsolicited packets received from other subscriber served by the same operator (e.g. worms exploiting subnet discovery protocols such as Internet Control and Management Protocol (ICMP) or Simple Service Discovery Protocol (SSDP); and (c) malicious packets.
A mobile device may not be able to block a network from sending packets, since a connection to the network or a call must be established and IP data examined prior to a packet's validity being determined. Packets from Stale IP sessions can be considered unsolicited packets. There are network and mobile device impacts which arise from unsolicited packets. First, the network impact is such that unsolicited traffic means inefficient use of network resources (sending undesired data to users), resulting in data delivery delays for other users as well as the possibility of complete network unavailability for voice or data service for many users within a geographic area. Second, the device impact is such that unsolicited traffic means a mobile device may be paged to set up calls on an ongoing basis, resulting in very rapid battery drain as well as erroneous accounting of data usage records for a particular data capable mobile device. Thirdly, receiving undesired unsolicited traffic can be irritating to customers.